PC(22:5(7Z,10Z,13Z,16Z,19Z)/16:1(9Z)) is a phosphatidylcholine (PC or GPCho). It is a glycerophospholipid in which a phosphorylcholine moiety occupies a glycerol substitution site. As is the case with diacylglycerols, glycerophosphocholines can have many different combinations of fatty acids of varying lengths and saturation attached at the C-1 and C-2 positions. Fatty acids containing 16, 18 and 20 carbons are the most common. PC(22:5(7Z,10Z,13Z,16Z,19Z)/16:1(9Z)), in particular, consists of one chain of docosapentaenoic acid at the C-1 position and one chain of palmitoleic acid at the C-2 position. The docosapentaenoic acid moiety is derived from fish oils, while the palmitoleic acid moiety is derived from animal fats and vegetable oils. Phospholipids, are ubiquitous in nature and are key components of the lipid bilayer of cells, as well as being involved in metabolism and signaling.While most phospholipids have a saturated fatty acid on C-1 and an unsaturated fatty acid on C-2 of the glycerol backbone, the fatty acid distribution at the C-1 and C-2 positions of glycerol within phospholipids is continually in flux, owing to phospholipid degradation and the continuous phospholipid remodeling that occurs while these molecules are in membranes. PCs can be synthesized via three different routes. In one route, choline is activated first by phosphorylation and then by coupling to CDP prior to attachment to phosphatidic acid. PCs can also synthesized by the addition of choline to CDP-activated 1,2-diacylglycerol. A third route to PC synthesis involves the conversion of either PS or PE to PC.

This compound belongs to the class of organic compounds known as phosphatidylcholines. These are glycerophosphocholines in which the two free -OH are attached to one fatty acid each through an ester linkage.

Has transacylase and calcium-independent phospholipase A2 activity. Catalyzes the formation of 1-O-acyl-N-acetylsphingosine and the concomitant release of a lyso-phospholipid (By similarity). May have weak lysophospholipase activity.

PA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides. This isozyme hydrolyzes more efficiently L-alpha-1-palmitoyl-2-oleoyl phosphatidylcholine than L-alpha-1-palmitoyl-2-arachidonyl phosphatidylcholine, L-alpha-1-palmitoyl-2-arachidonyl phosphatidylethanolamine, or L-alpha-1-stearoyl-2-arachidonyl phosphatidylinositol. May be involved in the production of lung surfactant, the remodeling or regulation of cardiac muscle.

Selectively hydrolyzes arachidonyl phospholipids in the sn-2 position releasing arachidonic acid. Together with its lysophospholipid activity, it is implicated in the initiation of the inflammatory response.

PA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides. Has a powerful potency for releasing arachidonic acid from cell membrane phospholipids. Prefers phosphatidylethanolamine and phosphatidylcholine liposomes to those of phosphatidylserine.

Transporters

Mediates ATP-dependent export of organic anions and drugs from the cytoplasm. Hydrolyzes ATP with low efficiency. Human MDR3 is not capable of conferring drug resistance. Mediates the translocation of phosphatidylcholine across the canalicular membrane of the hepatocyte